✓ Forty-six patients with cerebral arteriovenous malformations (AVM's) were selected for embolization with bucrylate. These patients were assigned to three different groups. Group I consisted of 22 patients with nonresectable AVM's who were selected for embolization with a Silastic calibrated-leak balloon. In 16 of these patients, embolization was achieved, with partial obliteration of the AVM in 14 and complete obliteration in two. Five patients had subarachnoid hemorrhage caused by the balloon bursting and concomitant dissection of the feeding vessel. Four of these patients recovered completely and one died of a brain-stem hemorrhage. A permanent field defect was noted in five cases, and two patients had a transient mild neurological deficit. Group II consisted of 13 patients treated by intraoperative embolization. Complete obliteration by embolization was obtained in four cases, and complete surgical resection after embolization in five. Partial embolization with no surgical resection was achieved in five cases. Three of these patients had a permanent mild neurological deficit and two had transient deficits. There was no mortality in this group. Group III consisted of 11 patients treated by embolization with bucrylate using a new latex calibrated-leak balloon. This balloon has a higher malleability, and takes on the exact configuration of the feeder, with no risk of dissection. This balloon also permits delivery of a faster and larger injection of bucrylate to the arterial feeders of the AVM. Two AVM's were completely obliterated, and embolization was only partially successful in the other cases. Neurological complications consisted of incomplete field defects in two cases, slight memory loss in one case, and transient clumsiness of the arm and face in one case. Two patients have a catheter permanently glued in the malformation, with no neurological complication. There was no mortality in this group.
Experience in 46 cases
Gérard Debrun, Fernando Vinuela, Allan Fox, and Charles G. Drake
Review of 16 cases
Gyula Gács, Fernando Viñuela, Allan J. Fox, and Charles G. Drake
✓ True congenital peripheral aneurysms of the cerebral arteries are rare and may constitute a special group. The authors report on 16 cases of peripheral aneurysms of the cerebellar arteries; six of them arising from vessels feeding arteriovenous malformations (AVM's). The possible causative role of increased blood flow versus developmental factors in the frequent occurrence in cases of AVM of this otherwise rare type of aneurysm is discussed. In five of the six cases with AVM's (one dural and five parenchymal), the aneurysm rather than the AVM proved to be the source of the hemorrhage. The occurrence of spasm was in inverse proportion to the distance of the aneurysm from the main arteries. The surgical result was good in 11 cases. One patient with associated AVM died, and four patients had residual symptoms.
Fernando Viñuela, Allan J. Fox, Shinichi Kan, and Charles G. Drake
✓ A case is reported of a large spontaneous right posterior inferior cerebellar artery fistula in which the patient presented with a right cerebellopontine (CP) angle and right cerebellar syndrome. The patient was successfully treated by balloon occlusion at the fistula site. The location of the arteriovenous fistula, the mass effect of its enlarged draining veins on the cerebellum and CP angle structures, and the simple therapeutic endovascular occlusion with a detachable balloon make this case unique.
Significance of angiographic morphology of the posterior communicating arteries
David M. Pelz, Fernando Viñuela, Allan J. Fox, and Charles G. Drake
✓ The clinical and angiographic records were reviewed for 71 patients with giant aneurysms of the posterior circulation, who underwent therapeutic occlusion of the basilar artery or both vertebral arteries. This treatment is used when the aneurysm neck cannot be surgically clipped, and occlusion of the parent artery is performed to initiate thrombosis within the lumen. In these cases, collateral blood flow to the brain stem is supplied mainly by the posterior communicating arteries. Consequently, their angiographic morphology (patency, size, and number) is demonstrated as a preoperative indicator of whether the patient will be able to tolerate vertebrobasilar occlusion. Vertebral angiograms with carotid artery compression (the Allcock test) will often be needed to provide this information.
The data relating posterior communicating artery morphology to clinical outcome in 71 cases of attempted vertebrobasilar occlusion are presented. The use and accuracy of carotid artery compression studies are also discussed. It is essential for the radiologist to supply the neurosurgeon with this valuable information in every case of giant posterior circulation aneurysm.
Report of three cases
Matthew F. Omojola, Allan J. Fox, Fernando V. Viñuela, and Charles G. Drake
✓ This is a report of spontaneous regression of intracranial arteriovenous malformations (AVM's) in three female patients; two of these patients had complete angiographic disappearance of the AVM, including an instance of intimate association of the AVM with an astrocytoma. The AVM's in these two patients were unicompartmental medium- to large-sized lesions supplied by a single feeder and draining principally through one large vein; spontaneous thrombosis is suggested as a cause of the AVM regression. Partial regression in the third patient might have been partially due to embolism from a clot-filled aneurysm on the feeding vessel. The significance of such disappearance of AVM's in relation to persistence or otherwise of the neurological status of these patients is discussed.
Fernando Viñuela, Allan J. Fox, David M. Pelz, and Charles G. Drake
✓ Fourteen patients had classical angiographic findings of intracranial dural arteriovenous malformations (AVM's). They presented with unusual central neurological signs and symptoms, including visual disturbances, hemiparesis, speech disturbances, gait ataxia, diffuse increased intracranial pressure, and intracranial hemorrhage. In 12 of the 14 patients there was a direct correlation between the clinical presentation and the venous drainage characteristics of the AVM's. The symptoms were probably related to a regional steal phenomenon in two patients. Six patients had direct surgical excision of the dural AVM. Five patients underwent endovascular embolization of the malformation and, in one case, the AVM was removed surgically after embolization. In one patient, the external carotid artery in the neck was ligated. Ten of the 14 patients had substantial clinical improvement or cure. A complete anatomical obliteration of the malformation was obtained in seven cases. None of the patients deteriorated clinically after therapy.
Fernando ViñUela, Charles G. Drake, Allan J. Fox, and David M. Pelz
✓ An intracranial varix is rare and has been associated mostly with vein of Galen fistulae or arteriovenous (AV) malformations. The authors present eight cases of intracranial, pial or subpial AV fistulae with concomitant giant varices. Six were supratentorial and two were infratentorial. Only one case involved the vein of Galen. In six cases successful surgical and/or endovascular occlusion of the intracranial AV fistula was obtained, and one case was treated conservatively. Staging of surgery and postoperative hypotension were considered to be important in avoiding edema and hemorrhage following obliteration of a large AV shunt. One patient died from delayed postoperative intracerebral bleeding.
Experience with 20 cases
Fernando Viñuela, Allan J. Fox, Gerard M. Debrun, Sydney J. Peerless, and Charles G. Drake
✓ Sixty-five carotid-cavernous fistulas were studied at University Hospital, London, Canada, from 1978 to 1982, 20 of which fulfilled the clinical and angiographic criteria of a spontaneous carotid-cavernous fistula. Of these 20 fistulas, 17 were unilateral, and three were bilateral. In 18 cases the angiographic findings were typical of an arteriovenous malformation (AVM), and in two a ruptured giant intracavernous aneurysm was found. These patients were treated according to whether they had a nonresolving or progressive cavernous sinus syndrome or deterioration of vision. The cavernous dural AVM's were treated with polyvinyl-alcohol and/or isobutyl-2-cyanoacrylate (IBCA) embolization of the external carotid artery blood supply. Two patients underwent postembolization surgical procedures. The detachable balloon technique was used to occlude the fistulas associated with the two giant ruptured intracavernous aneurysms and a small dural intracavernous AVM. Eight patients received no therapy; in two, spontaneous obliteration of the fistula occurred. Of the nine cavernous AVM's embolized with particles and/or IBCA, successful transvascular embolization was achieved in seven cases, and partial embolization followed by surgery in two cases. Successful balloon obliteration of the giant intracavernous ruptured aneurysm was obtained in two cases. In one patient, right hemiplegia with aphasia resulted from reflux of IBCA emboli through the artery of the foramen rotundum into the left middle cerebral artery.
Gérard Debrun, Pierre Lacour, Fernando Vinuela, Allan Fox, Charles G. Drake, and Jean P. Caron
✓ A series of 54 traumatic carotid-cavernous fistulas has been treated with detachable balloon catheters. The balloon was introduced through one of three different approaches: the endarterial route; the venous route through the jugular vein, the inferior petrosal sinus, and the cavernous sinus; or surgical exposure of the cavernous sinus; with occlusion of the fistula by a detachable balloon directly positioned in the cavernous sinus. Full follow-up review demonstrated that the carotid blood flow was preserved in 59% of cases. The most frequent complication was a transient oculomotor nerve palsy, which occurred in 20% of cases. In three cases where both the fistula and the carotid artery were originally occluded by the balloon, the superior portion of the fistula was later found not to be completely occluded, and these patients had intracranial ligation of the supraclinoid portion of the carotid artery. Three patients had hemiparesis, transient in two cases and permanent in the other. The results show that the fistula was totally occluded in 53 cases; in the one exception the patient became asymptomatic but had a minimal angiographic leak.
Allan J. Fox, Fernando Viñuela, David M. Pelz, Sydney J. Peerless, Gary G. Ferguson, Charles G. Drake, and Gerard Debrun
✓ Of 68 patients with unclippable aneurysms treated by proximal artery occlusion with detachable balloons, permanent occlusion was achieved in 65; of these patients, 37 had carotid artery aneurysms below the origin of the ophthalmic artery, 21 had aneurysms arising from the supraclinoid portion of the carotid artery, six had basilar trunk aneurysms, and one had a distal vertebral aneurysm. Examination for treatment selection included assessment of the circle of Willis by compression angiography and xenon blood flow studies, with the ultimate evaluation being test occlusion under systemic heparinization with the balloon temporarily placed in the desired position. Of 67 patients who underwent a formal occlusion test, eight with carotid artery aneurysms did not initially tolerate the occlusion test, and ischemic signs disappeared instantaneously with deflation and removal of the balloon. During test occlusion, two additional patients had ischemic events that proved to be embolic; these reversed immediately upon balloon deflation.
Of the 65 patients in whom permanent occlusion was effected by detachable balloon, there were nine instances of delayed cerebral events. One of these was a seizure leading to respiratory arrest and resuscitation 3 days following occlusion in a patient who had presented with seizures. The other eight cases were delayed ischemic events; seven were completely reversed and one patient had residual weakness in one leg (1.5% permanent morbidity). Extracranial-intracranial bypass procedures were performed in 25 of the 65 cases. All aneurysms of the carotid artery below the level of the ophthalmic artery presented angiographic proof of complete thrombosis. Ten of 21 aneurysms arising from the supraclinoid portion of the carotid artery were completely thrombosed by proximal occlusion alone, without additional trapping procedures. Similarly, in three of six basilar trunk aneurysms, proximal occlusion alone initiated complete aneurysm thrombosis without trapping. The conclusion is that proximal balloon occlusion for unclippable cerebral aneurysms is a convenient, safe, and effective way of producing arterial occlusion in these cases.